loop string set

Question

[aj123]

There seems to be something wrong with the code below; im not sure if it is the indentations because im getting a different result each time if i change the indents; I'm not sure which is the correct way to indent.

 fh = open("df_1.csv")
 readr = csv.reader(fh) 
 header = next(readr)
 header
 data = [row for row in readr]
 names = set()
  for row in data : 
   mapID = row[1]
     for n in mapID :
    names.add(n) 
 len(names)

[rpolicastro]

This isn't really a bioinformatics question, but we can't really answer the question regardless without understanding what your input and desired output look likes.

[aj123]

im trying to get the number of genes (names). the desired output is a number. input is a csv file.

[rpolicastro]

The number of unique gene names? And the names are in the second column of the CSV file?

[aj123]

yes that is correct

[rpolicastro]

You can just do something like this then.

fh = open("df_1.csv")
readr = csv.reader(fh) 
header = next(readr)
header
data = [row for row in readr]

names = set(x[1] for x in data)
len(names)